1. Field of the Invention
The present invention relates to a solenoid-operated valve for discharging a reaction gas and/or residual water from fuel cells of a fuel cell system.
2. Description of the Related Art
Solid polymer membrane fuel cell devices have a stack of cells each comprising a solid polymer electrolyte membrane sandwiched between an anode and a cathode that are disposed one on each side of the solid polymer electrolyte membrane. For operating such a stack of cells, hydrogen is supplied as a fuel to the anode and air is supplied as an oxidizing agent to the cathode. Hydrogen ions are generated at the anode by a catalytic reaction, and move through the solid polymer electrolyte membrane to the cathode where they cause an electrochemical reaction to generate electric power.
The above fuel cell devices have an air compressor or the like for supplying air as a reaction gas to the cathodes of the fuel cells, and a pressure control valve for supplying hydrogen as a reaction gas to the anodes of the fuel cells under a pressure depending on the pressure of the air, using the pressure of the air as a signal pressure. The pressure of the reaction gas applied to the anodes with respect to the cathodes is regulated to a certain pressure by the pressure control valve for achieving a predetermined power generating efficiency, and the rate of the reaction gas supplied to the fuel cells is controlled to obtain a predetermined output level.
KEHIN CORPORATION has proposed a residual water discharging device for discharging residual water from fuel cells (see Japanese Laid-Open Patent Publication No. 2002-305017). The proposed residual water discharging device has a cathode drain valve disposed at a suitable position in an air passage in the fuel cell system, for discharging air and residual water from the fuel cell system, and an anode drain valve disposed at a suitable position in a hydrogen passage in the fuel cell system, for discharging hydrogen and residual water from the fuel cell system.